Long-Term Follow-Up of Restorations of Equine Cheek Teeth Infundibula (2006–2017)

Background:Caries of the infundibula of equine cheek teeth can lead to significant dental disease including increased attritional wear, pulpar and apical disease, secondary sinusitis, and dental fracture. Restorations of cavities of equine cheek teeth infundibula have been performed since 1889. Recent advances in dental materials, instrumentation, and techniques have facilitated the use of dental restoration techniques by equine veterinary practitioners. No studies to date have demonstrated the safety or efficacy of restorations of equine cheek teeth infundibula.Objectives:To assess the long-term results of restorations of equine cheek teeth affected by infundibular caries, to report on the safety of the procedure, and to give guidelines for future restorative therapies.Study Design:Retrospective analysis of results of clinical and oroscopic examination of horses that underwent infundibular restoration procedures between 2006 and 2017.Methods:A total of 223 infundibula in 185 maxillary cheek teeth in 92 horses were restored using a variety of dental materials including glass ionomer cement, flowable and compactible resin composites. The time between restoration and re-examination was recorded along with findings of clinical signs in the interim, restorative material loss, and any further pathological changes of the teeth including caries progression, fracture, or apical disease. Follow-up examinations were performed over two study periods 2006–2012 and in 2017.Results:Over the full study period, 99% of treated horses available for follow-up examinations had no adverse clinical signs or developed any abnormalities of restored teeth observable on oroscopic examination. Of horses re-examined, 83% of restorations were shown to have minimal or no loss of the restoration material, with occlusal surface wear visibly comparable to other adjacent maxillary teeth. Statistical analysis showed success of the procedure was related to the restorative material used, the restoration technique, and the caries grade present at the time of restoration (grade 2 is more successful than grade 3).Main Limitations:There are no case controls in this study and therefore it is not clear if restoration of equine infundibula is a consistently beneficial procedure, or at which grade of caries progression restorations should be performed for optimum benefit. The procedures were not re-examined at consistent regular times creating some difficulties in standardizing results. Re-examinations of treated horses did not consistently include radiography or computed tomography and therefore some apical changes may have occurred in treated teeth without visual oroscopic or external clinical signs.Conclusion:Restoration of equine infundibula using materials developed for human dentistry including flowable resin composites is a safe and long-lasting procedure and appears to prevent the development of further pathological changes including apical infection and dental fracture.

Clinical Considerations in Orthodontically Forced Eruption for Restorative Purposes

For restorations on teeth involving invasion of the supracrestal tissue attachment (biological width), as well as for lack of ferrule effect, crown lengthening is required for long-term periodontal health and success of the restoration. In the same fashion, site development is often necessary prior to implant placement in order to provide optimal peri-implant soft and hard tissue architecture conducive to future esthetics and function. Orthodontic extrusion, also known as forced eruption, has been developed and employed clinically to serve the purposes of increasing the clinical crown length, correcting the periodontal defect, and developing the implant site. In order to provide comprehensive guidance on the clinical usage of this technique and maximize the outcome for patients who receive the dental restoration, the currently available literatures were summarized and discussed in the current review. Compared to traditional crown lengthening surgery, forced eruption holds advantages of preserving supporting bone, providing improved esthetics, limiting the involvement of adjacent teeth, and decreasing the negative impact on crown-to-root ratio compared to the traditional resective approach. As a non-invasive and natural technique capable of increasing the available volume of bone and soft tissue, forced eruption is also an attractive and promising option for implant site development. Both fixed and removable appliances can be used to achieve the desired extrusion, but patient compliance is a primary limiting factor for the utilization of removable appliances. In summary, forced eruption is a valuable treatment adjunct for patients requiring crown lengthening or implant restorations. Nonetheless, comprehensive evaluation and treatment planning are required for appropriate case selection based upon the known indications and contraindications for each purpose; major contraindications include inflammation, ankylosis, hypercementosis, vertical root fracture, and root proximity. Further studies are necessary to elucidate the long-term stability of orthodontically extruded teeth and the supporting bone and soft tissue that followed them.

Effect of CAD/CAM Ceramic Thickness on Shade Masking Ability of Discolored Teeth: In Vitro Study

Shade matching is a common challenge that dentists face during fabrication of esthetic dental restoration. Thus, the aim of the current study was to assess the masking ability of two types of CAD/CAM ceramics for gaining high esthetic prosthesis. This in vitro study used a total sample size of 66 lithium disilicate (LD) and leucite reinforced (LR) CAD/CAM ceramics sub-grouped into three thicknesses: 0.5, 1, and 1.5 mm. Nine shades of natural dentin die materials were prepared as a replica of the underlying tooth structure. The difference in color (ΔE) and translucency parameter (TP) were assessed for both tested ceramics at the three thicknesses. One-way ANOVA was performed to compare the three thicknesses of each ceramic, followed by multiple pairwise comparisons between both ceramics. LR had significantly higher ΔE than LD at all thicknesses used unlike the case in TP. Thickness of 0.5 mm exhibited the highest ΔE and TP, while 1.5 mm thickness showed the lowest ΔE and TP in both ceramics. Increase in ceramic thickness had a great impact on both color masking ability of the underlying tooth structure and its translucency. The higher the ceramic thickness, the better the masking ability and the lower the translucency was reported.

EVALUATION OF STRENGTH PARAMETERS OF POLYMER COMPOSITES USED FOR DENTAL RESTORATION BY THE METHOD OF ACOUSTIC EMISSION

The aim of the study is to create a technique and perform mechanical tests to determine the strength parameters of dental composites from the standpoint of linear fracture mechanics, and using the phenomenon of acoustic emission to determine the origin and development of destruction of light-curing dental composites under quasi-static local compression load. The following hybrid dental composites of domestic and foreign manufacturers were selected for comparison: Latelux (Latus, Ukraine), TETRIC N-CERAM (Ivoclar Vivadent, Liechtenstein), CHARISMA CLASSIC (Kulzer, Germany). 10 disc samples of 13 mm diameter and 5 mm thick of each material were made by using a specially designed mould for study purposes. Packaging and moulding of the material into the mould was performed in laboratory conditions at an air temperature of 18 – 21°C. Before testing, the samples were kept for 24 hours at a temperature of 37°C in saline solution. The samples were loaded on the SVR-5 machine using a ball indenter. During the experiments, acoustic emission data were simultaneously recorded using the SKOP-8 measuring system. In the post-processing stage, the dependencies of the load change during the experiment, the distribution of the amplitudes of the registered AE signals and their sum over time were recorded. The fracture load, indenter displacement, and the features of composite fracture were determined from the obtained dependencies based on the analysis of AE generation under the load. Analysis of the parameters of the AE signals showed that during the destruction of the Tetric N-Ceram composite the signals had the largest amplitude and energy, and of Latelux had the smallest ones.

The translucency of human teeth and its relation to esthetic restorative materials

The main factor that can determine the harmonization and depth of color restorations for the adjacent other restorations or other teeth is the translucency of these restorations. Many factors can affect the translucency and color of the restoration material, including translucency parameter, lighting conditions, opacity, gloss, light scattering, and overall perception by the naked eye. Previous investigations have indicated that translucency is the main factor that can significantly contribute to the esthetic characteristics of the different dental restoration materials. In the present literature review, we have discussed the translucency of human teeth and its relation to esthetic restorative materials. Comparing the translucency of the different restoration materials with the naturally occurring human enamel is essential for adequate validation of their clinical application. It has been demonstrated that for 1 mm thick human enamel, a mean value for the translucency parameter of 15-19 should be considered. We have also highlighted the differences between the different types of resin composites and different shade groups, and findings indicate the superiority of some types and shade groups over others, as previously discussed. However, it should be noted that further research is still needed to unify the variously estimated values for the translucency parameter among the different restoration materials. This can help clinicians adequately interpret these data and obtain satisfactory clinical and patient-related outcomes.

Use of Nanocomposite Resin Materials for Dental Restoration in Elderly Patients

Tooth defects can affect not only periodontal tissue but also the whole body if not restored in good time. Composite resin materials are commonly used filling materials in dental restorations, but they have low material strength and are likely to cause insufficient secondary caries. Improving the ability of composite resin materials to restore defective teeth has thus become the focus of research interest. Nanocomposite materials are widely used in dentistry because of their good design characteristics, wide indications, strong restorative power, and high economic efficiency. However, whether they cause respiratory tract inflammation or tissue damage due to their large specific surface area still needs further investigation. This study compared the effects of nanocomposite resin materials with those of traditional light-curable composite resin materials on the restoration of dental defects in elderly patients and found that nanomaterials could not only reduce the incidence of tooth sensitivity and tooth pain after restoration but also improve the aesthetic outcomes of the tooth. In addition to the restoration effect, the occurrence of adverse reactions in patients who underwent dental restoration using nanomaterials within 2 years after the procedure was significantly lower than that in patients who underwent dental restoration using traditional materials. These results indicate that the nanocomposite resin material improved the restoration effect in elderly patients without increasing their risk for adverse reactions. Therefore, nanocomposite resin materials should be used as the preferred filling material for dental restoration in elderly patients with dental defects.

Clinical assessment of Filtek Bulk Fill Posterior dental restorative meterial

At present we notice how much all processes in the world accelerated. This concerns both our life and healthcare, in particular, dentistry. Patients become more demanding and informed, they value their time, in turn, young doctors need much more time for restoration by layer-by-layer application of the material, than experienced doctors. In this context, a material is required that will permit to reduce the time of restauration. The article presents the results of assessment of the effectiveness of Filtek Bulk Fill Posterior restorative material of 3M ESPE manufacture in the practice of an aspiring dentist. The findings were assessed according to the criteria for assessments of restorative materials (Ryge’s criteria), by aesthetic appearance quality (AAQ) and also by the quality of direct dental restoration on the stage of rehabilitation.

Fatigue of full crown monolithic CAD/CAM restorations for posterior teeth

Objective The purpose of this study is to estimate the fatigue life of five polycrystalline zirconia CAD/CAM ceramic materials used for posterior restoration. This study presents the first time methodology to translate raw data obtained from laboratory test into useful data to predict the clinical life of dental restoration. Methods A typical model for the first molar restored crown is built and transferred into finite element software ANSYS 18.1 flor execution FEA. The materials are: two Y-TZP zirconia (LAVA (LVs), and EVEREST (KVs); IPS e.max CAD; Suprinity PC; and Celtra Duo. Two types of loads are applied, axial load and axial load followed by the sliding motion of lower jaw. The fatigue resistance of various restorative materials is determined. Results Experimental findings show that all the samples have fractured between cusps at the same location, which is slightly off the symmetry fissure plane. For crowns made of LAVA and EVEREST, the life is longer than 10 years under an axial load of 1000 N, while the lives for IPS e.max CAD; Suprinity PC; and Celtra Duo were longer than 10 years under an axial load of 185 N. The life of all-ceramic crown materials was predicted by FEA and found to conform to previous experimental and clinical observations. Conclusion Crowns made of Y-TZP zirconia has superior fatigue resistance compared to other ceramic CAD/CAM materials.